// https://leetcode.cn/problems/set-matrix-zeroes/submissions/

class Solution {
public:
    void setZeroes(vector<vector<int>>& matrix) {
        if (matrix.empty()) return;
        int m = matrix.size();
        int n = matrix[0].size();
        bool reci = false;
        bool recj = false;
        for (int i = 0; i < m; ++i) {
            if (!matrix[i][0]) reci = true;
        } 
        for (int j = 0; j < n; ++j) {
            if (!matrix[0][j]) recj = true;
        }
        for (int i = 0; i < m; ++i) {
            for (int j = 0; j < n; ++j) {
                if (!matrix[i][j]) {
                    matrix[i][0] = 0;
                    matrix[0][j] = 0;
                }
            }
        }
        for (int i = 1; i < m; ++i) {
            if (!matrix[i][0]) {
                for (int j = 0; j < n; ++j) {
                    matrix[i][j] = 0;
                }
            }
        }
        for (int j = 1; j < n; ++j) {
            if (!matrix[0][j]) {
                for (int i = 0; i < m; ++i) {
                    matrix[i][j] = 0;
                }
            }
        }
        if (reci) {
            for (int i = 0; i < m; ++i) 
                matrix[i][0] = 0;
        }
        if (recj) {
            for (int j = 0; j < n; ++j)
                matrix[0][j] = 0;
        }
    }
};